Automatic clamshell bucket



y 1941' F. CAOLI 2,242,940

AUTOMATIC CLAMSHELL BUCKET Filed March 28, 194.0

2 Sheets-Sheet l INVENTOR M QRNEYS,

May 20, 1941. F, CAOL, t 2,242,940

AUTOMATIC CLAMSHELLBUCKET Filed March 28, 1940 2 Sheets-Sheet 2 INVENTOR w M ATTORNEYS Patented May 20, 1941 UNITE OFFICE Claims.

This invention relates to buckets of the clam shell type, and has for an object to provide an improved and simplified construction which is automatic in operation to lock the bucket closed and retain it closed until released by the operator, and when dropped in the open position on to material to be raised or excavated and tension is placed on the lifting cable, the laws will be automatically closed and locked in this position.

It is also an object to provide a bucket of this type which does not require an extra cable with its necessary complications of pulleys, etc. for opening and closing the bucket.

Another object is to provide a bucket of this type of simplified and improved construction which will be efllcient and effective in operation, and which is not easily gotten out of order.

With the foregoing and other objects in view I have devised a construction as illustrated in the accompanying drawings forming a part of this specification. It will, however, be understood that various changes and modifications may be employed within the scope of the invention.

In these drawings:

Fig. 1 is a side elevation of a bucket involving my improved construction with the jaws in closed position and with certain parts broken away to more clearly show the construction;

Fig. 2 is a similar side view showing the jaws in the open position;

Fig. 3 is a view looking from the right of Fig. 1;

Fig. 4 is a transverse section substantially on line 44 of Fig. 2;

Fig. 5 is a section substantially on line 55 of Fig. 6;

Fig. 6 is a vertical central section looking from the left of Fig. 1 and on an enlarged scale; and

Fig. '7 is a section substantially on line 7-1 of Fi 6.

The improved bucket construction shown is of the clam shell type comprising two jaws I l each having upwardly extending arms II pivotally supported on bearings I2 on a supporting member I3. The jaws shown are of the closed or solid type, but it will be understood that I am not limited to the use of such jaws, but may use a rake arrangement or jaws having projecting studs or teeth at their lower inner edges. Located above the supporting member I3 is a block I5, and this block has a pair of pivot bearings I6 projecting from each end from which are suspended supporting links I? pivoted at their lower ends at It to the two jaws of the bucket, preferably at the inner sides of the end walls, and at points below and outwardly of the pivotal connections I2 of the arms of the jaws to the support I3.

Slidable in the block I5 is a hollow shaft I9 having at its lower end a rounded head 20 with a shoulder 2!. The shaft also carries a collar or flange forming a shoulder 22, and embracing this shaft is a coil spring 23 abutting at its opposite ends against the shoulder 22 and the block I5. This spring normally tends to force the shaft I9 downwardly and carry the head 20 toward the support it, and under certain conditions to cause it to interlock with a catch on this support, which will presently be described. Secured to the upper end of the shaft I9 is means for connecting thereto a lifting chain or cable 24. This in the present showing comprises an eye 25 mounted in a block 26 which is in turn mounted in the upper end of the shaft I9 by any suitable means, such for example as screw threads or Welding. To assist in keeping the parts in alignment and facilitate guiding action between the shaft I9 and block I5 and also to insure that the lower end of the shaft is brought into proper relation with the support I3, a second shaft 21 is slidable within the shaft I9 and connected at its lower end, as shown at 28, to the support I3.

The cooperating locking means on the support l3 for under certain conditions locking the shaft I9 to this support, comprises a slidable catch member 29 having a projecting extension 39 adapted to engage over the shoulder 2| on the shaft I9. It is slidable within the housing 3i and is normally held in the projected position by a spring 32. The rear end of the cavity in which the catch is mounted is open as indicated at 33 to prevent accumulation of dirt and dust within the cavity. Pivoted to this support at 34 is a forked-lever 35 carrying a transverse pin 36 extending through elongated longitudinal slots 3'! in the opposite sides of the housing and vertical slots 38 in the side arms of the lever 35. It also projects through the catch 29 and serves as a means for connecting the catch to the lever and retracting this catch when the lever 35 is swung outwardly or to the right as shown in dotted lines Fig. 6. For operating this catch a flexible cord or light cable 39 may be connected to the lever 35 and carried to the operator in the cab or other position for operation of the bucket. The lifting cable 24 leads over the usual guide sheaves or pulleys on the boom to the winding drum in the lifting apparatus.

The operation is as follows:

When the jaws are filled and are being lifted they are closed as shown in Fig. 1. At this time strain is on the cable 2t and shaft I9, and the shoulder 2i at the lower end of this shaft is under the projecting end 30 of the catch 29 on the sup port I3 so that this shaft is locked to this support. The pull on the shaft I8 and on the support I3 raises this support and the pivots [2 carried thereby so as to swing the jaws about the pivots I8 and retain them in closed position. When the bucket has been raised and. carried over the lo cation where the material is to be dropped, as for instance in a truck, the operator pulls the cord 39 thus withdrawing the catch extension 30 from. over the shoulder 2|. The weight is so distributed that the support I3 and the pivots I2 immediately drop turning the jaws about the pivots I8 and thus separating the lower ends of the jaws or opening them and discharging the material held thereby. The jaws are now in the position of Fig. 2, and as the strain of the weight is stillon the cable 2d and the shaft lfi this shaft is retained in its uppermost position and with the spring 23 compressed. The jaws are then carried in this position back over the material to be excavated and dropped in this position down into this material. As the tension is removed from the cable 24 the spring 23 expands to move the shaft I9 downwardly to carry its head 20 and shoulder 2i toward the support I3 and carry the shoulder 2! under the projection 38 of the catch 29. To facilitate this action the outer surface of the head may be inclined or curved as shown, and the upper surface of the extension Silmay also be similarly shaped, so as to give the desired camming'action to retract the catch 29 and to permit the head 20 to move past the extension 36 to the position shown in Fig. 6. Then astension is placed on the cable 2 3 it draws'the shaft I9 together with the support I3 and pivots I2 upwardly swinging the jaws inwardly about the pivots I8 and thus closing the jaws. Atthe same time it compresses the spring 23 to the position shown in the drawings preparatory tothe next operation of shifting the shaft I9 when strain on the cable is released after dropping the open bucket into the material to be excavated. It will thus be seen that the jaws are automatically locked. closed and remain so until the catch 25) is again released by pulling on the cord 39.

It will be also seen that this is a simple and effective mechanism which does not require a separate cable for opening and closing the jaws, 1

but these are automatically closed by tension applied to the lifting cable and are automatically held closed until the interlocking connection between the shaft l9 and the support I3 is released. Having thus set forth the nature of my invention, what I claim is:

1. In a 'device' of the character described, a supporting member, a pair of bucket jaws pivoted'to said member, a block above the supporting member, supporting links pivoted to the block and to said jaws below the pivots to said memher, a shaft secured to said member and slidable in the block, a hollow shaft enclosing the first shaft and slidable in the block, a catch on the supporting member adapted to engage and hold said second shaft to hold the jaws in closed position, a spring tending to shift the hollow shaft to engage said catch, means for connecting a lifting cable to said hollow shaft to lift the jaws, and means for releasing said catch to permit the jaws to open.

2. In a device of the character described, a support having pivots, a pair of bucket jaws having arms hung on said pivots, a shaft secured to said Support, a second shaft slidable on the first shaft and having a shoulder, a block slidalble on the second shaft, links pivoted to the block and to said jaws, means for securing a lifting cable to the second shaft, a catch on the support adapted to engage said shoulder and by tension on the cable to move the jaws to closed position, a spring tending to move the second shaft to engage-the catch, and means to release the catch to permit the jaws to open.

3. In a device of the character described, a'

support, a pair of bucket jaws pivotally mounted on said support, a shaft secured to the support, a second shaft slidable on the first shaft, means for connecting a lifting cable to the second shaft, a block in which the second shaft is slidable, supporting links pivoted to the block and to the jaws, a spring tending to move the second shaft toward the support, cooperating means on the latter shaft and. thesupport to'lock the shaft to the support so that tension on thecable will lift the support to close the jaws, and means for releasing the locking means to permit the jaws to open. a V

4. In a device of the character described, a support, a pair of bucket jaws having upwardly extending arms pivoted to the support, a block above the support, supporting links pivoted to the block and to the jaws below and outwardly of their pivots to the support, a hollow shaft extending through and slidable in the. block, means for connecting a lifting cable to the shaft,

' a spring tending to move the shaft toward the support, cooperating means on the shaft and the support to lock the shaft to the support so that tension on the cable will lift the support to close the jaws, a second shaft secured to the support and guided for sliding movement inthe first shaft, and means for releasing the locking means to permit the jaws to open.

5. In a device of the character described, a support, a pair of bucket jaws pivotally mounted on said support, a block, supporting links pivoted to the block and to the jaws ahollow shaft extending through and slidable in said block, means for connecting a lifting cable to said shaft, a spring embracing the shaft and tending toshift the shaft toward said support, cooperating means on the shaft and the support to lock the shaft to the support so that tension on the cable will lift the support to close the jaws, a second shaft secured to the support and slidable in the first shaft, and means to release the locking means to permit the jaws to open.

. FRANK CAOLI. 

